- There is not a pattern of "illegal immigration," most of the people are nationals of the UK. Among those who are migrants, they are more likely to have come for study or economic reasons than for political reasons or as refugees.
- To the degree that they are religious, they are relatively new to religion and not well versed in it.
- They are no more likely than than any other part of the population to suffer from psychological disorders.
- They are not unified by any particular national or ethnic origin.
- While most are under the age of 30, this cannot be said to be typical of the group.
- Among those over 30, they are more likely than not to have families.
- No general claims can be made about whether they are likely to have completed formal education or not.
Is there anything that can be said the people in the group studied? Perhaps a few things:
- It is not sufficient to be exposed to extreme ideas or to be persuaded by them. People are recruited into groups and remain in them by means of personal contact.
- People who have experienced marginalisation or racism or who have only held low-level jobs may be more receptive to recruitment than others.
- The tolerance of terrorists for people with criminal records (here they refer to ordinary rather than "political" crime) may mean that people who are not accepted elsewhere in society may be accepted by terrorist groups.
- The people recruiting members into terrorist networks are less likely to be the famous "radical clerics" as they are to be peers from the communities in which the recruits live.
- The strongest force maintaining members in the group is a sense of belonging.
- Perceptions of racism, anti-Muslim sterotypes in media, and other information that promotes a sense of victimhood strengthen recruitment.
There is of course another distinction to be made: between having extreme ideas and using violence to realise these ideas. Here (this is not a quotation from the report, which I have not seen, but from a summary of it by Alan Travis in the Guardian):
"The MI5 authors stress that the most pressing current threat is from Islamist extremist groups who justify the use of violence "in defence of Islam", but that there are also violent extremists involved in non-Islamist movements.If this is the way that thinking is developing among people in law enforcement about terrorism, it is a good sign. Concentrating attention on where the trouble might be rather than on where it is could have the effect of producing more terrorists.They say that they are concerned with those who use violence or actively support the use of violence and not those who simply hold politically extreme views."
Update: That last point is made more colourfully at SpyBlog (which also discusses the possible provenance of the document) -- "One Obvious Question not mentioned in the "Key Points" or in The Guardian's articles, is to what extent "radicalisation" is influenced by the cockups and mistakes whereby heavy handed or inept Police and Security Agency actions, which sweep up innocent or neutral or marginal terrorism supporters, and who refuse to promptly admit, publicly apologise and make generous financial compensation for their mistakes, contributes to the conversion of these people and their relatives, into more extreme supporters or into actual terrorists, exactly as used to happen in Northern Ireland."